Improvement in devices for drilling coal and rock



a. FLETCHER. A

Devicesfor Dril'lingrCoal and Ruck. 4 l 10,1146522I Patented1an.`20.`1\874`.

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To all whom it may concern: i Be it known that I, ROBERT FLETCHER, ofBrookfield, in the county of Trumbull and i l State of Ohio, haveinvented a certain new and Improved Device for `Drilling Coal and Rock,of which the following is a full and complete description, referencebeing had to the accompanying drawings making part of the same. y

This invention is for holding a drill and feeding the same whiledrilling coal and rock, the construction and operation whereof is asfollows:

Figures l and 2 are front and side views of the device. Fig. 3 is ahorizontal transverse section.

Like letters of reference refer to like parts in the several views.

A represents a wooden frame. B is a yoke secured in the frame byset-screws C inserted in the arms D of the yoke, thereby forming a clampembracing the outside of the frame, as `shown in Fig. 3. In said yoke isfitted a nut, consisting of the two parts E F, which are retainedtherein by a key, G, and also whereby the two'parts of the nut areforced together in order to `close upon the screw H. The screw referredto is intended to hold the drill, and 1, for this purpose a hole is orshould be made in `the end of it for the insertion of the drill.

The `practical application and operation of the device above` describedare as follows: The frame A is set up endwise in the mine, as shown inFigs. 1 and 2, near the wall of coal,

and in this position fastened by any appropria-te means. The drillinserted in the screw is ,now operated by turning the screw from theother end. The progressive movement of the UNITEE STATES PATENT OFFICE.

ROBERT FLETCHER, OF BROOKFIELD, OHIO. y i

IMPROVEMENT IN DEVICES `FOR DRILLING COAL AND ROCK.

`Specification forming part of Leiters Patent No. 146,522, dated January20, 1874; application filed i November 5, 1873.

screw feeds the drill into the `coal or rock, as the case may be, asfast as it cuts its wayin. The drilling may be done at any particularheight by adjusting the yoke to such height by means of the set-screw C;also, the drilling maybe done at any particular anglebyturning the yokeand nut above or below a horizontal line, for which purpose the ends ofthe set-screws serve as pivoted points for the adjustment of the nut.

It will be observed that a thread ,is cut` in each side of the two partsof the nut, the purpose of which is that, when the thread on one side ofe'ach part of the nut is worn out, the sections can be reversed, therebyfurnishing the screw with a new nut or thread. In closing the two partsof the nut by means of the key they are made to bear equally uponthescrew, so that the nut will wear evenly the entire length of the thread,there being no more pressure on one side of the nut than upon the other,which would not be the case were the two parts hinged to each other.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. Theyoke B and key G, in combination withA the two-part nut,consisting of the sections E F, in the manner substantially as and forthe purpose set forth.

2. The two'part nut herein described hav` ing a thread cut upon eachside ofthe two sections, substantially as and for the purpose set forth.

ROBERT FLETCHER..

Witnesses:

J. H. BURRIDGE, A. F. CORNELL.

